Watch the Bb Minor Baby online guitar lesson by Jeff McErlain from 50 Eclectic Blues Licks You MUST Know
Here is a cool minor blues with a bridge. Adding bridge is a great way to spice up a blues and it is usually done by going to the IV chord. Famously James Brown would yell "Take it to the bridge!" and the band would know that would be the IV chord which certainly made things easier on the band stand!
The final turnaround in the bridge is the same progression Stevie Wonder uses on "Higher Ground".